Dry-pipe sprinkler-system accelerator



Oct. 30, 1928. 1,689,980

E. TYDEN DRY PIPE SPRINKLER SYSTEM ACCELERATOR Filed Feb'. 15, 1926 2sheets-sneet 1 Oct. 30,1* Vv1928. n'

Y E. TYDEN DRY PIPE sPnINxLER SYSTEM AccELERAToR 2 Sheets-Sheet 2 FiledFeb. l`5, 1926 AZS 5215021226: .5'.

ess.

qui

the accelerator.V j l r The drawings .showithe niain rahecasing A, withthe Watersuppiy pipe, B,and,fpipe= C, leadingto the lsprinkler `headsysteur,ailf

'in said casing', ,being reerred to as the (Z, entering the casing,opens into Valve chamber "Valve, Of-,herernatter more p sage, G3, intothe chamber, rh

Patented v, Oct. 30, 1928.

UNiTED fsTATEs- PATE EMIL TYDEN,v oF EVANsaJoN, I'LLiINoIs'.

`"mur-PIPE srRmKLER-sirsrnm AGCEILERATOR.

i Lppucauonnied February ,The purpose of this inreution is to provide animproved constructuni of an accelerating device fora dry pipesprinidersystem; It

consists of the elements and features `of con-l struction shownanddescribedk as indicated in the claims. f

In the drawings Figure l is a trout elevation ot the dry' line `eti-4 ion be rond the main Water-controiiin9'vaive .a

e r 4 i "3 pressure region ofthe system.

Connected with thejair pressure regione"` the connection as shownbeingrinade by pipe,

` D, which is y connected mitin and' ieaes from,

the cavity ofthe main Valve casingeis the accelerator device indicatedas to its entirety,` by `reference letter E, and con'iprising anAattached part, F. ,r

Ithis accelerating,lr i device` c oi casing having two cha1nbers,l0anwhich the air pressure region et thesy: communicates,- uari5`fAdescribed, 1 by and (1,3, in .said casing.

oipassages,

the pipe, D, by vcoiniection Wit-h the -pipe 1iinb,1 46, hereinaftermentioned, said pipe, i i at a port el, 'which 0*, Vdiei-ein -a 'L' i del r der@ scribed as its mounting' connectionsfroopera rta la waivev sr(il, having a port, 621eadin0' c "by, its periphery.v line 3--3 onchambers come inunicate `With the air` pressure regnen of the 1 a systemby means ot,apipepd,lead-nigtrom ali one, as shown f15, 192e. serial No.88,167.

one, as shown at 16; andupon thisouter Wall of the using, E, there isappiied av cap, e, havia in its applied i'ac-e a large cav-ity, 17, withitsiarge aperture reggisteringv with the aperture, lt, in the Wall ofthe chamber, 11, v and having' a small aperture, 18, registering withthe aperture, l5, inthe wail uof the chamber, l0. A duct, 19, connects.the..cavity,

.17, With the aperture, 1S. :in thecavity, V17,

there is mounted a" diaphragm casing condprising two inenibers, 2O and21, between which a flexible diaphragm, is cianipefdV The diaphragmcasing" member, 21hasapertures, Q1, :tor communication. oi the diaphragmchamber at one side 'ofthe diaphragm through the duct, 19, With- 'thechan'iber, 10, andthe diaphragm casingy ,ineniheig 20,; has apertures,20, 'for commu nica-tion ot' the diaphragm chamber at the other-'side ofthe dia ihraoni With the chain- Y M zo ,p Y Y ber, 1l. e n a Thepressure troin'the air pressure region of the system, itwillybefseen,reachesthe chamber, li, t'reeiy through the port, 63, so r that changesinthe pressure in said air" presf sure regionwiil. be experiencedproinptyin ,i

said chamber, 11.

But saidprcssure reaches NT omcEL-j the chamber, 10, by Way ofthepassages, 13

and 12, and a fitting, H, which is interposed," inthe passagel2, orbetween the saine and posed thereinhaving an aperture,fh1, con#` astituting thesoie access of pressure .from the lduct, l2, to thechamber, l0. The detail con struction of this iitting Will be understood,troni the drawing as comprisingr plugs, H1,

H1, screwed into the oppositeends ot fthe body nieniberpH, of thetitting, Veach carrying a perforated or Woven wire strainer element, h2,for ,guarding the restricted a perture, h1, againstch hing by dustparticles. f

vits opening-into the chaume-1310, the passagel -for pressurecommunication through the fit` tinQI-I, beingaestricted `by a disk,h,intere` Atfwili bel seen that theqdiaphragm, 2Q,

-constitutes in effect an impertorate'partition separating the twochambers 10 and 1l, so far as air communication betweenthein is con#1 icer-ned, but subject to the communicationfoff,

ot "the pressures- Which. reach the opposite s ies, ot the diaphragn'ivthrough th'erespee .Y pressure from the onetothe other by Virtue@ T ichani- Y tire apertures ot the diaphragm casing nit-:lin-` Y ber. In thediaphragm casing atthe sideto# Ward' the chamber, 11j, there isi mounteda5 f Y f1 plunger, 24,-har1ng an expandedhead, 25f0r seating on thediaphragm, the plunger itselt obtaining bearing and guidance in a.bearing, 20", with which the diaphragm casing member is provided at itscenter projecting into the chamber, 11. The end of the plunger protrudesfrom said bearing lor encounter with the. inner end of an operatingmember. t), which. as hcreinaiter more particularly described, extendsair-tight through the wall of the chamber, 1l, for a functionhereinafter more particularly explained.

'the part. F. primarily ati'ords a, eounectvitm with the air pressureregion ol' the system through which itis vented to the atmosphere g :mdlor that purpose it has a cavity or passage, 39, which opens at one endthrough a port, fl-1, at which the pipe, D. is connected, said pipeleading. as hereinarlter mentioned, trom. the air pressure region of thesysteni. This port. il, is controlled by avent valve, if), cti-operatingwith a scat. ft2, tormed at the outer side ot said port` 41. At the sideot the passage, 23S), said passage opens to atmosphere through the port,lt), wherebywhen the valve lil. is open. the pressure of the airpressure region ot' the system is freely and promptly vented andrelieved.

The valve, lo. has its stein, guided in a bearing seen at 18; and belowthat bearing the casting. F, is ehambered, as seen at. 49, toaccommodate a coiled spring, 5l, which reacts between the lower side ofsaid guide bearing, 418, and a collar, 5U, screwed onto the lower end otthe, valve stem. Llel, for initially holding the valve normally seated,and retractin g it 'from open position to its seat on which it isadapted to be. held b v the air pressure ot thesystem when the entireapparatus is set Incidentally the collar. 50, by titting quite closelyapproximately piston-wise in the stem chamber, 4S), which iscylimlrically bored, operates to prevent sudden retraction ol' the valveto its seat with ay hammer blow there on. and causes it on the contraryto seat with conmaratively slow movement without hammer. Below thespring chamber the part, F, has a cavity. open at the lower end whereit'. registers with an. aperture. 2G. in the flange, 2i". which projects'trom the web of the hol- `low base, 28. ot the easing, E. in which basethe weighted lever, 122, `whose Function is hereinafter described, ispivotally mounted and housed.

An important purpose of the construction. being to cause the vent valvet3 to be opened by the movement of the operating part, 30, which resultsfrom the movement ot the diaphragm, 22, upon the. limited. reduction otthe pressure in the air pressure region ot the tem. is effected by theoperating connections from the part, 30, to the vent valve stem, whichwill now be described.

Said member, 30. is pivotally mounted in the lower wall of the chaniber,l1, tllrongh which Wall it protrudes and is rendered airtight at itsprotrusion therethrough by means ot'l a tlexible sleeve. 90, whose upperend is clamped tightly about an enlargement, 91, of said operating.rmember. 30, while the lower end is similarly clamped about the boss, 92,formed around the aperture through which said operating member protrudestrom the casing. A convenient construction for the purpose is thatshown, which consists of a plug, 95, which closes an aperture, titi. inthe lower end wall ot the chamber, 1l, and which has at its upper sidethe boss. 92, mentioned, upon which the lower end of the ilexiblesleeve, 90, is made fast, said plug, 95, being secured in positionclosing the aperture, 9G, by a screwed-in follower. ltlt). Thist'ollower, 100, is apertured to admit the upper forked part, 110, of aweighted bell crank lever. 111, said lever constituting a latch memberhaving its latch nose. 112. engaging the tlange, 105. which is formed atthe lower end of thev follower. 100, by counterboring its upper endportion. This bell crank lever is t'ulcrulned near its angle on aweighted lever, 122. which will be shortly described` and has itshorizontal arm quite heavily weighted, as seen at 113, 'tor eil'ectingautomatic engagement ot the latch nose. 112, with the flange` 10.3. asdescribed. Said end of the bell crank lever is engaged by the lower endof the operating member, 30, ilor disengagement oi the latch nose bypivotal rocking of lsaid operating meniber, which occurs when ,its upperend is moved inward by the inward thrust ot' the plunger, 24, whichresults from the reduction of pressure in the chamber, 11, consequentupon the reduction of the pressure in the air pressure region ot thesprinkler system, which may be caused by the opening of a sprinklerhead. The weighted lever, 122, is fulcrumed near one end on pivot studs.of which one is indicated at 123, set in the wall or web, 28. ot thecasing, E, having its opposite end weighted as seen at 122 for gravitymovement for giving a powerful upward thrust by the shorter end oi thelever. for opening the vent valve by connections. For this purpose thereis pivotally connected to the lower end of the valve stem, i4, a swinginlink, 130,1which extends down through the open lower end of the chamber.52, for engagement with a stud, 131. on the lever, 122, said linkterminating in a cam projection, 130, at the upper limit of which there,is formed an abrupt shoulder, 130", with which the stud, 131, collidesafter the initial down ward swing of the weighted end of the. lever hascaused the stud, 131. operating on the cam terminal, 130, to swing thelink, 130. a short distance to the right at its lower end; and upon theencounter of the stud with the shoulder 130b the l'urther down-swing ofthe weighted en d of the lever causes the stud, 131, to give an upwardthrust to the link. and thereby to the valve stem, 44, liftingr the valve,

43, vfrom its seat, and accomplishing the venting which is thepurposeofthe connection.

, Since such venting ofthe air pressure causing the main valve to beopenedjby Vthe water pressure would cause the system to `be floodedwithwater, and since in the absence of preventive Vmeans the watercoming to occupy the entire air pressure region oi' the system wouldfollow the conduit through which the air pressure reaches theaccelerator chambers, and flood those chambers, a urtherpurpose of theconstruction is to cut off the communicationfrom the air pressureregionof the system to ,the accelerator `afterthe vent valve is openedas above described. ,The construction for this purpose will now bedescribed.

The valve, 60, which controls access of the air pressure to theaccelerator chambers, is held normally open by spring device 66m,hereinafter more particularly described, which reacts for that purposebetween a disk,

66p,` loose on the stem of the valve and stoppedl and 66, ofgwhich thepart, 65, is screwed` into the part, 66, for clamping said disk be tweenthe shoulders `of the two parta Thel part, 66, is hollow from end toeiid,they part,`

65, beingr screwed into one end closingv the cavity and leaving theremainder of its length to the opposite end operating as a 4socket oryguide bearing, as indicated at 66a, .for the end ofthe stem, 7 7 Oiadisk, 68, which is secured to thecentral portion` of a diaphragm, 69,`which partitions a ,diaphragm chamber formed lby a recess, 70, intheeuter surface of the left-hand upright end of the part, F, and atio-,operating recess, .71',in the right-hand face of an applied vcapplate, 72, the two recesses being bounded by annular seats between whichthe margin of the diaphragm is clamped by bolts which securethe. capplate to the part, F Said cap plate has Vat the lower side a. cavity, 73, `opening at one end into the recess, 71, and at the lower. endthreaded for connection afforded by a pipe, 74, `which leads from a partof the system to which the water pressure has access only when the` mainvalve isopen, and which is `connected for drainage when the water supplyis cut off.

Thecavity'lthrough which stem, 77, extends `from its end guided in thesocket, 66, of thestem ofthe valve, 60, traverses at Vrightanglesthefcavity, 52, and is bored at the end next to thejdiaphragmchamber to house and form a stop shoulder for a spring, 78, which reactsbetween said stop shoulder, 79, and the centralhub of the disk, 68, forholdingthe Adiaphragm normallyflat, and the stem, 77, `out of touch withthe end of the part, 65, ojf the stem of the valve, 60, whichforms thebottom of the socket in which the stem, 7 7, is guided.

the diaphragm carries a cioss-pin, 77h, engaging slots, 130", -l

in the two fork arms oi' the link, 130, so 4that the sideI swing of thelink, caused by the encounter of the stud, 131, with the cam terininal,130, of the link, thrusts Lthe stein, 77, into touch with the end of themember,6, ofthe stem ofthe valve, 60. Simultaneously upon the venting ofthe system pressure by opening the vent` valve, 43, the water supplyYpressure enters and quit-e rapidly follows up the escaping air in thesystem, and, reaching the diaphragm, 69, through the pipe, 7 4, forcesthe diaphragm inward causing the stem, 77, to thrust the valve, 60,ully'to its seat, cut-ting off access ot the system pressure,

and thereby preventing the entrance olwatei f the link, 130, laterally,dislodging the shoulder, 130", from the stud,131,whereupon theV spring,51, reti-acts the vent valve, 43, toits -seat,'preventing the waste ofthe water which would otherwise occur through the vent dport, The stressof the spring, 78, upon the stein, 7 7, transmitted to the link,130,bythe'engage# ment of the cross-pin, 77", in the slots of the fork armsof the link, holds the link stressed against the side of the stud, 131,at'the posi#y tionof the link for holding the valve, 60, closed; and theweighted lever, 122, pendent, holds the stud, 131, in the positioniiorthus locking the valve, 60, closed until said pendent y lever ismanually lifted for resetting the apparatus after the system has beendrained of the water, and it is desired to recharge the! air pressureregionwith airiinder pressure.

The specic detail form yof the Vspring device,66m, for holding the,valve, 60, `normally open, is a crimped or corrugated spring tubecommonly known as a sylphon, which therefore enclosesa chamber aroundthe valve stem, 65. It will be understood that the sylphon device isitself open at both ends'and that the disks, 64 and 66p, do not close itair` tight at either end; on the contrary, the sylphon is at all times,as necessary for its normalspring acti0n,-open to discharge and entranceof air as it is compressed and reacts by expansion. It is therefore opento the air bers; and it will be understoodthat this air l derivedthroughthe diaphragm, 69, for seat' ing the valve, GO, and for holding itseated, and reacting for opening said valve. For convenience ofinstalling the valve, 60, with its twoanembered stem, (35, 6G, and thischamber spring device by mounting in the casing, E, there is providedthe casing, GG", which encompasses and encloses the sylphon spring, 66m,and affords a guide bearing for the hollow stem member, titi, and a stopfor the same in the direction of thrust ot' the sylphon spring. as seenin Figures 2i. 4- and 5. This casing. (36", is screwed into a bored andthreaded recess in the casing casting, E, and is thereby in position forentry of the hollow boss at its left-hand end in which the Istem member,66, obtainsl seat and guidance in an aperture provided for it in thcproximate wall of the part., F, when the latter is assembled inpermanent relation to the easing, E. The purpose of this specificconstruction is to eiiectually protect the valve. (50, from any accessof water to it. or past it, into the accelerator chamber.

As mentioned above, the pipe` 7l, for water connection to the (liaphragmchamber to operate the diaphragm, 69, for the purpose described mustlead from a point in the s) 'tem to which the water pressure has accessonly when the main valve is open for admitting the pressure to thesupply system, and since it is desirable that the diaphragm chambershould be drained to permit the diaphragm to recover its normal positionand release the valve, G0, when the system is drained of water, and isto be reset with proper pressure in the air pressure region, the pipe,74, should lead from a point in the system which is open for drainagewhen the system is drained preparatory to resetting. Both theseconditions are met by connecting the pipe, 74, with the customary alarmpipe, 80, which leads from the interscat chamber, Si, of the main valvecasing, in which there is shown the familiar construction for drainageof said interseat chamber when the main valve is seated, and when thesystem is set for operation, consisting of the drainage connection, 85,for closing which there is provided a valve 8G, which is held open whenthe main valve is closed by the finger, 88, extending from the mainvalve through the main valve port for encounter with one end of thelever, 89. by

which the valve, SG, is carried at the other end.

A v ery important consideration determining the construction forcontrolling the valve by which the system pressure is admitted to theaccelerator chambers, is that it is liable to occur through inattentionthat the system air pressure by reason of some minor leak declines soslowly that the differentiation of pressure in the two chambers of theaccelerator does not occurg-that is, the restricted communicationbetween the two chambers is equal in flow capacity to the leak; with theresult that this decline of pressure does not cause the accelerator toact for venting the system air pressure, and otherwise operating thedevice. In such case the leali continuingr until the system air pressurebecomes less than the water supply pressure, the main valve opens andthe system is flooded when there is no :Tesina-that no tire to beextingu'f":-d: and in the absence oi preventiw means, the entire systembeing filled with water, the *at'er follows where the air pressure hadpreviously and normally followed. into the accelerator chambers, andthat: device becomes flooded, with the elliect frequently otA depositot' sedimentary material at `'arious places in the device, and in anyevent the accumulation of water in pockets from which there is nodrainage and from which none can be readily provided. In such case it ispractically necessary to dismount and disassemble the entire acceleratorin order to clean it of a deposit. and restore its eflicieney.

An important purpose of the construction shown in the drawings is toovercome this defect and prevent the undesirable flooding of theaccelerator. The specific means for this purpose consists in thepressure connection afforded by the pipes. S() and 7i leading from thechamber, Si, ot the main valve casing to the dialihragm, (if), connectedas descril'ied for closing the valve, (30, cutting oiil access of bothair pressuwy and water pressure from the accelerator chambers.

It will be observed that the eliiciency of the construction shown forseating the valve, (50, under the circumstances indicated, depends uponthe fact that. t he pressure which operates for seating it, beingderived from the same source as the pressure which normally operates forholdingr it open ,--is thus operative by virtue of the excess of thearea of the diaphragm over that of the valve. And it will be furtherobserved that the result desired.- viz, the closing of the valve, (it),when the main valve is opened so that from that opcning there. may notresult. access of water to the accelerator chambers,-will be obtainedwhether the pressure which operates through the open main valve in thechamber, 84, and thence through the pipes, 8O and 74;, to the diaphragm,(39, is the renmant of air pressure in the system, or is the waterpressure from the supply pipe, and that therefore the valve, (it), willbe closed upon the (mening of the main valve, even though by oversightor intention the water supply may at that time be cut oli' by theclosing of the shut-oit valve which is customarily present (but notshown in the drawings) in the water-supply pipe, Bg that is to say,primarily and fundamentally it is the access of pressure, from whateversource from above the main valve, to thc diaphragm which is atlorded bythe opening movement'ot the main valve, that accomplishes the resultdescribed.

inn

` ment upon limiteddecline of pressure in the air pressure region of thesystem; a movable part caused to be moved by said means; an atmospherevent portand a conduit leading thereto romthe airnpressure region of thesystem; a valve controlling'said` port positioned forbeing normally heldseated by the pressure in the air pressure region of the sys- ,y

`tem, and operative connections `from said vzo movable partforopenings'aid valve against the air pressure of the system; means forautomatically locking said valve at open position, andV means loperatedby the Water pressure, admitted as theresult of venting the airpressure,` for automaticallyY releasing the Y Vlocking means to causesaid valve to be closed y `means caused to" operate for producing move-Y vbythe pressure resulting in the air'pressure region, from theadmission of the `Waterpressure.

trolling valveftherein, adapted to be held seated against the Waterpressure by the-air pressurein the system, a device comprising ment uponlimited decline of pressure in the air pressure region of the system; amovable part caused tobe moved by said means; an

` atmosphere vent port 'and `aconduit leadinglthereto from" theairpressure region of y thesystem; a valve cont-rolling said port y ytopermit the` vent "valve to'be closedby mi und yielding means kforholding it normally seated ;operatingconnections from said movable partfor openingr said valve; means forV automatically locking said valve atopenpo'sition, and means operating automatically upon the admissionofthe Water pressure to the system for/releasing said lockingmeans saidnormally closing means.y 1 i 3. In a dry pipe sprinkler system, incombinationwith a ,valve casingI and a Water controlling valve thereimadapted to be held seated againstthe Water pressure by the air .pressureinthe seat-a device comprisingmeans causedto operatefor producingmovement upon limiteddecline of pressure in-the Y air pressure region ofthesystem; a movable y part causedto move by said means; a port for jventing theair pressure region vof the system;

a normally seated vent valve controllingsaid1port;poperating;connections from said movable -partforV opening the,vent ,valve upon decline of pressure in the air pressure region;

y automatic means for lockingl said vent valve at,A open position;-avalve` for controllingac- `cess of system air` pressure tothe`firstmentioned device; Voperating connections rttor clos-V 2. Ina drypipesprinkler systenn'in combination with a Valve casing and aWater-con- `ing said last'mentioned valve comprising a lpart arrangedfor deriving valve closing movement consequentupon theventing ofthe Vairpressure, said operating connectionsbe'- ing connected also forreleasing the vent Valve locking means.

In the construction definedinclaim l, a normally open valve controllingcommunication of the accelerating device with the air pressure region ofthe system, connections operated by said movable part for seatingI saidvalve .in the movement for opening the vent valve, and means'in saidconnections 'for locking `said normally open valve at seated.

position WhileV thevent valve is open; vvhereby air pressure to theacceleratingvdevice' is automatically 'cut off When said system airpressure is vented to the atmosphere;` s

5, In the'construction deiined in claim l,

afvveighted lever Whichis normally locked at upheld position otiteWeighted end; means operated by'said Vmovable part for re-l leasing thelockingfmeans to permit the lever `to fall; the connections Vfor`operati-ing" the,

vent valve being engaged with said Weighted lever by means of which thefalling loff-the.

lever forces open the vent valve, and the lever at 'fallen positionlocks the vent valve open;

said connectionscomprising a linlzcon'nectedf at one end With the ventvalve stem and4 attlie` other end engaged by the lever forlongitud inalthrust vto open the vent valve, and for simultaneously swingingdaterallyabout said pivotal connections; a valve which controlsaccess ofthesystem air pressure to the accelerating device, and means engagedWith :said link and connected With said last men-f tioned valveorclosing said valve infthe lateral movement of the link'ivhich occurs yin theV thrust movement by ,which the vent y is opened.

6.V In the construction dened in claim4 l, a

valve which admits the systemair pressure to Y the i accelerating device;A the connections Which are caused to operate by theV movement of said`movable part for opening the yvent valve being adapted forsimultaneously closing said air-pressure-admitting; valve and comprisingthe means :tor locking the vent valve open; a chamber having amovingvvall ivhose cavity communicates with a part of the system towhich thewater pressure has access only'upon the main valve being open,

and operating connections from' said moving` Wall constituting the meansfor releasing the vent valve locking means; whereby the vent valvecloses when the Water pressure admitted to the system, for preventingthewater Wasting at the vent port, and thewater is,

simultaneously excluded n, from the `acceleratonL 7. In the constructiondeined in claimi; a

valve torcontrollingaccess of the system or pressure to the acceleratingdevice, means for closing said valve connected for such closing l zomovement with the vent valve opening means, and means operated b v thewater pressure admitted upon venting the air pressure tor automaticallylocking said valve closing means in valve closing position.

tw. The structure delined in claim l havinkcr an alarm operating' waterconnection leading .from a point in the main valve casing at which theintake of such connection is cut oil from both the air pressure and thewater pressure when the main valve is seated and is open to the watersupply pressure when the main valve is open; a valve which controlsaccess ot' the pressure from the air pressure region ot' the system tothe chambers oi. the accelerating device; and means tor seating: saidvalve connected to said alarm operating water pressure connection. y

9. In a dry pipe sprinkler system, in combination with a main valvetherein mounted and connected for being opened by the water supplypressure and held seated by the system air pressure, said systemhaving;r a drainage chamber which said main valve when seated cuts oli'from h oth the water supply pressure and the system air pressure, and towhich the water pressure has access when the main valve is opened; anauxiliary device and a conduit for communicating the system air pressurethereto: a normally closed vent valve in said conduit Vl'or ventinar theSystem pressure to the atmosphere; chambers in said auxiliary device towhich said system pressure is communi 'ated through said conduit;mechanical connections which are actuated upon decline of the system airpressure for opening the vent valve and holding it. open against thenormally closing means; an element adapted to he moved hy the waterpressure, and connections from the drainage chamber for so movingr saidelement, and operative mechanical connections trom said movable elementto the means tor holding the vent valve open for releasing the ventvalve to permit it to be closed by the normal closing means.

10. In a dry pipe valve sprinkler system, in combination with a mainvalve casing: and a main valve therein mounted and connected forbeingopened hy the water supply pressure and held seated by the systemair pressure, said system ha vintr a drainage chamher which the mainvalve when seated cuts ott trom both the water supply pressure and thesystem air pressure. and to which the water pressure has access when themain valve is opened; an auxiliary device havin, T chamhers; a conduitthrough which the system air pressure is eonnnunicated to said chambers;a valve controllingr said communication: said conduit having anatmosphere vent port and a valve controllingV said port: means broughtinto operation by Said auviliarv device tor opening the vent valve andholdingr it open; an element adapted to be moved b v fluid pressure andconnection from the drainage chamber tor so movingr said element, andmechanical operating connections trom said n'lovable element 'orreleasing the vent valve from the means holding it open` and closing:rthe valve controlling access of pressure to the chambers of theauxiliary device.

ll. In a dry pipe sprinkler system, in combination with the main valvecasing and a main valve therein mounted and connected 'lor beine` openedby the water supply prcssure and held seated hy the system air pres-.surel` said casing;r having a drainage chamber which said main valvewhen seated cuts oti from both the water supply pressure and the systemair pressure and to which the water pressure has access when the mainvalve is opened; an auxiliary device and a conduit for coimnunicatingthe system air pressure thereto; a normally closed vent valvel in saidconduit for venting the system pressure to the atmosphere, said valvepositioned with respect to its seat for helingY held seated by thesystem air pressure; chambers in said auxiliary device to which saidsystem air pressure is communicated through said conduit, a, normallyclosed shut-oil valve lor controllintr the system air pressure connection to the chambers of the auxiliary device; mechanical connect-ionswhich are actuated upon decline ot the system or pressure i'or openingthe ventvalve and holdincr it open against said system air pressure; anclement adapted to be moved by the water pressure, and connections fromthe drainage (,hambcr for so moving said element, and operating4mechanical connections Alrom said movable element to the means forholding.; the vent valve open l'or releasing aidvalvc, said(,:onnections extending to and simultaneously operatingr said normallyopen valve for closing the same when the vent valve is opened.

l2. l'n a d ry pipe sprinkler s vstem in combination with a valve easingand a water-controlling valve therein adapted to he held heated againstthe water supply pressure by the system air pressure, said systemcomprisinga chamber which the main valve when seated cuts otl from boththe water supply pressure and the air supply pressure; a conduitleadimcr from the air pressure region of the system l'or connection withan auxiliary apparatus. said conduit havin" an atmosphere vent port, avalve controlllner said port which is normally closed, means actuatedupon decline ot the system air pressure for opening the ventport-controlling*r valve. means for locking said vent port-controllinervalve in open position, the connections for causingr the closing of saidatmosphere vent valve operating for that purpose b v releasing saidlocking means. Y

13. In combination with a dry pipe, sprinkler system, an accelerating'device for hastenine reduction of pressure in the air pressure region ofthe system having a passage for communication with said region andadapted to beset 1n operation by decline of pressure in said region, thesystem compris-V ing a conduit connected with said air pressure regionfor freely venting the pressure therein to the atmosphere; a vent valvecontrolling said conduit, said accelerating device coinprising a chambertoy which the pressure V'from the air pressure region has access, amovable,

part mounted for movement in response to change in said pressurereaching said eha1nber, and mechanical connections from said movablepart for causing the opening of said atmosphere vent valve, saidconnections compris'ing a part extending. from Within said chamber andprotruding airtight out through the Wall thereof, and other parts eX-terior to said chamber brought into opera tion for opening saidatmosphere vent valve .by said protru ing part, said exterior parts 1

